1. Field of the Invention
This invention relates to an insulating end cap construction for a cylindrical electrolysis cell of the type comprising at least two tubular electrodes arranged coaxially, one within the other, with a cylindrical membrane arranged coaxially between them.
2. Description of the Prior Art
Cells of the type to which the invention relates can be used for example for sanitising water through electrolysis for drinking purposes, or electrolysing brine solutions to make a powerful biocide. Many types of electrochemical activation and electrolysis cells exist for this purpose, and generally comprise two concentric cylindrical electrodes, one of which acts as a cathode and the other as an anode, an ion-permeable membrane being located coaxially between them to separate the space between the electrodes into anode and cathode compartments. An electrolyte such as brine is passed through the anode and cathode compartments, separately or successively. When brine is electrolysed in this way, under suitable conditions, it can produce a sporicide solution of high strength and long shelf life, which is ecologically and human friendly.
One type of concentric cylindrical cell of the type to which the invention relates is disclosed in published European Patent Application No. 922788. This discloses an electrolytic cell in which the two concentric electrodes and the membrane are received in unitary end bushes, each having a central aperture for passage of the inner electrode with surrounding concentric seatings for the membrane and the outer electrode. Cells of this type function quite well, but a problem arises in their construction. A high degree of craft skill is required to assemble them, and in particular to assemble the cell components in the end bushes, and there is a high breakage rate. With brittle ceramic cylindrical membranes, damage rates can be as high as 1 in 5.
It is accordingly an object of the present invention to provide an end cap for an electrolytic cell which is easy to fit and reduces the likelihood of breakages.
It is another object of the present invention to provide a cylindrical cell which is leak-free and pressure-resistant. Many existing cells start leaking over a period of time as component parts are mechanically sealed with gaskets. During the lifetime of a cell, component parts become brittle, shrink or expand, causing leakages.